Fig. 5

Genome content–based network (a) and genome organization (b–c) of viruses infecting Methylobacterium. a A gene content–based network was built to evaluate the relationship of five glacier-ice viruses to 484 viruses from other environments, all predicted to infect Methylobacterium (see “Materials and methods”). For clarity, viruses that were not connected to any of the five glacier-ice viruses were excluded from the network. Each node represents a virus, with glacier-ice viruses and others shaped in triangle and circle, respectively. The edge between nodes indicates the distances between two viruses. Viral clusters (VCs) are generated by vConTACT v2, and viruses that belonged to the same VC are indicated in the same color. In each VC, the name and source environment of each member are indicated, with glacier-ice virus at the top. All gray nodes represent viruses from other environments that did not share VC with any glacier-ice virus. b–c Genomic organization and comparison of Methylobacterium viruses that are longer than 15kb in VC0_0 and VC8_0 from (a). Only glacier viruses and their closely related viruses with genome size more than 15kb were illustrated, including four and four viruses from VC0_0 (b) and VC8_0 (c), respectively. Viral contigs were compared in terms of gene similarity, order, and direction (i.e., leftward or rightward arrow). Genes are coded in color based on their putative biological function. Potential microbial genes were identified by CheckV (see “Materials and methods”) and marked in green color. The predicted protein with no functional annotation is classified as “Hypothetical protein” and colored in gray. The gray lines indicate the amino acid identities between genes, as illustrated in the scale bar. Abbreviations: TransR, transcriptional regulator; MTase, mRNA methyltransferase; tRNASL, tRNA-splicing ligase; terS, terminase small subunit; terL, terminase large subunit; Mu N, Mu N gene product; DNARP, DNA repair protein; DNAM, DNA methylase; DNAP, DNA polymerase; RNAP, RNA polymerase; LytT, lytic transglycosylases; TransmP, transmembrane protein; DigC, diguanylate cyclase